Timing apparatus for traffic signaling systems



Septi 7; 1937.

C. H. BISSELL TIMING APPARATUS FOR TRAFFIC SIGNALING SYSTEMS Filed May 22, 1935 10 Sheets-Sheet 1 INVENTOR: {4,50 2067 49767 A; BY ZZ I T fl ' ATTORNEYd.

- Sept. 7, 1937.

C. H. BISSELL TIMING APPARATUS FO TRAFFIC SIGNALING SYSTEMS Filed May 22, 1953 10 Sheets-Sheet 2 INVENTOR.

Qlj'l 131-6381; BY flM W ATTORNEY5.

SCALE f FEET Sept. 7, 1937. c. H. 'BISSELL TIMING APPARATUS FOR TRAFFIC SIGNALING SYSTEMS Filed May 22, 1933 Sheets-Sheet 5 TOTAL PER/0D 556.

PERCENT swarms V eraser G? $2 39 &

TIME

/50 SECDA/D IN VENTOR.

can 5 Btssell, BY

ATTORNEYS.

p 1937. c. H. BISSELL TIMING APPARATUS FOR TRAFFIC SIGNALING SYSTEMS Filed'May 22, 1933 10 Sheets-Sheet 4 II ray-A TDTHL PER/00 -60 SEC IN SECONDS INVENTOR: Carl Bzlsaell, BY

ATTORNEYS.

$CALE f FEET TIMING APPARATUS FOR TRAFFIC SIGNALING SYSTEMS Filed May 22, 1933 Shegts-Sheet 5 I I E- 5 TOTAL PER/0D 5E6.

60 40 37 E E Q 53 \3 u 3; -70-a0 s 60-40 20 h Q R t 0040 54 0 50 I00 I50 EM 240 TIME IN SECONDS INVENTOR.

B (arl HBz'aaell, W *M AT'TORN E Y5 SCALE 0F FEET Sept. 7, 1937. c. H. BISSELL 2,091,954

TIMING APPARATUS FOR TRAFFIC SiGNALING SYSTEMS Filed May 22, 195 5 10 Sheets-Sheet 6 Ila--5- TOTAL PER/0D -60 SEC.

5pm" //v PERCENT &

OF/JET- IN 5:

T/HE

I00 I50 l/V SECOND-5 INVENTOR:

Carl HBiaaelZ, gfM/%m ATTORNEYS.

Sept. 7, 1937.

c. H. BISSELL 2,091,954

TIMING APPARATUS FOR TRAFFIC SIGNALING SYSTEMS Filed May 22, 1933 10 Sheets-Sheet 7 J1 E-IL TOTAL PER/0D 60 55.

SPL/ T IN PERCENTg I 9 i i g & F557- 4 film/V05 a: g 01 "a 200 //Y JECO/VOS' m TIME INVENTOR:

('arl HBiaaell, BY fi/MW ATTORNEYS.

SCALE FEET Sept. 7, 1937. c ss 2,091,954

TIMING APPARATUS FOR'TRAFFIC SIGNALING SYSTEMS Filed May 22, 19 33 Sheets-Sheet 8 Ins-.5.

TOTAL PER/00 c.

PERCENT Jim/V05 if 8 I50 JECO/VDS IN VEN TOR.

Q22! HBia'aell, WQWY ATTORNEYS.

Sept. 7, 1937. 'c. H. BISSELL 2,091,954

TIMING APPARATUS FOR TRAFFIC SIGNALING SYSTEMS Filed May 22, 1933 10 Sheets-Sheet 9 Q I! A A Y B Q m 501M773; N/ .[EfiJJO g Q '9 3 R 8 3 1: 3 R a g Q A Q &

- TOTAL PER/0D -90 65C I50 200 TIME IN SECONDS INVENTORI Carl 131195611,-

ATTORNEY5.

Se t. 7, 1937. c. H. BISSELL TIMING APPARA'I'US FOB TRAFFIC SIGNALING SYSTEMS l0 Sheets-Sheet 10 Filed May 22, 1933 JIE= l D Mns TER CONT/P04- OFFJET/05 %/07 I 50 Jar/9L Elwin q SPLIT INVENTOR: BY Carl 1 Bissell %M' fi m l O L ATTORNEYS.

Patented Sept. 7, 1937 PATENT OFFICE TIMING APPARATUS FOR TRAFFIC SIGNAL- DIG SYSTEMS Carl E. Bissell, Syracuse, .N. Y., assignor to Grouse-Hinds Company, Syracuse, N. Y., a corporation of New York Application May 22,

6 Claims.

This invention relates in general to circuit controlling apparatus for controlling a plurality of electrical circuits at different locations. For example, my circuit controlling apparatus is very A suitable for controlling a traffic signaling system wherein it is desired to control the signal circuits at a plurality of street intersections in-any particular order, and maintain the operation in such order.

This circuit controller is particularly adaptable to traillc signaling systems known as progressive systems, such as set forth in the Neill Patents Nos'. 1,723,060 and 1,723,062, issued August 6, 1929, wherein a plurality of intersections along a highway are signalized and the signaling system so operated that traffic on the highway may progress up and down, or in both directions with the highest efilciency. In such systems, various problems of circuit control arise, some of which are such that can not be solved with any circuit controlling device with which applicant is familiar Broadly, a progressive traffic signaling system is one operated so that the go signals progress successively up and down the highway. To those skilled in the art, it is understood that there must be maintained, a particular time relation between the signals at each intersection and that this time relation must be strictly maintained, otherwise, the system loses its efficiency to move traflic.

It has been found that the flow of trafiic on a highway is not constant throughout the day. Ac-

cordingly, any street including a progressive system that operates at high efliciency during one part of the day may operate to hinder trafllc during another part of the day. Also, it has been found desirable to vary the speed at different times of the day at which the trafllc signaling system is operated. It is highly desirable to have a system wherein these variations may be effected from a central point. My circuit controller is such that these adjustments can be made in the system and also be made from a central point.

To those skilled in the signaling art, it is understood that the total period is the time duration of a complete trafiic cycle, that is, the time during which the red light is displayed, the green light is displayed, and the amber or caution lights, if any, are displayed. Obviously, the shorter the total period the quicker each green light appears, and the quicker the green lights appear the greater the speed at which the system operates. It is therefore desirable to have circuit controlling apparatus for progressive signaling systems with which the total period of the signals in the system may be varied. 'An important object of my cir- 1933, Serial No. 672,207

cuit controller is the provision of means whereby the speed of the circuit controlling apparatus may be varied from a central point.

However, it is also obvious to those skilled in the art that increasing the speed at which the system operates does not necessarily mean an increase in the trafllc capacity of the system. As a matter of fact, increasing the speed alone materially reduces the platoon length of traflic moving through the progressive system. The length of the trafiic platoons depends upon the relative timing between one intersection and another, or more particularly, between adjacent intersections. If the green light at a succeeding intersection appears relatively early, or relatively late, the platoon of traflic passing through the preceding intersection will be stopped. The time relation between adjacent intersections of a progressive system is known as the offset. In as much as the traflic flow during part of the day may be heavy in a northerly direction, and during another part of the day heavy in a southerly direction, it is very desirable to have the system such that the offsets may be shifted to favor the heavier flow of trafilc at a particular time.

My invention has, as another important object, means whereby the time relation of the operation of the signals at each intersection, that is, the offsets, may be varied from a central point.

A third problem presented in progressive systems regards the split feature, or the relative duration of the red and green signals at each intersection. For example, at intersection A, the traflic flow on thecross street and on the highway may be substantially-equal, in which case, the duration of the red and green lights would be equal, or fifty-fifty percent, while at intersection B, the cross street might be of minor importance relative to the highway and the time relation between the red and green signals might be seventy-thirty percent. As the traffic flow varies also on cross streets, it is desirable to have circuit control apparatus by which these splits may be varied.

By my invention, I provide means whereby the split or time relation between the signals at each intersection may also be varied from a central point.

A fourth object of my invention is the provision of means whereby upon failure of any circuit between the central station and any of the intersections, or between any of the intersections the cycle timer and the signal circuit controller located at the street intersections.

Figure 2 is related to Figure 1 and is a schematic view and wiring diagram of the resynchro nizer and selector appartus associated with each secondary timer.

Figures 3, 4 and 5, are graphs depicting the flow of trafiic on a given street, as efiectedby change in ofiset.

Figures 6 and '7 are graphs showing the movement of trafiic on the same streets, with the same total period and ofisets, as shown in Figures 3, 4 and 5, and with the relative period ofdisplay of the redand green lights, or split, being different at certain intersections than that of Figures 4 and 5 respectively.

Figure 8 is a graph showing the trafilc flow resulting from decreasing the total period and employing the same relative ofiset.

Figure 9 is agraph showing tramc flow resulting irom increasing the total period and employing the same relative ofiset.

Fig. 10 is a simplified diagram in across-theline form of the electrical wiring system of the apparatus.

The invention comprises generally .a master circuit controller located at a central point, a

plurality of secondary circuit controllers each including a cycle timer for opening and closing -the signal circuits, a resynchronizing device for maintaining the cycle timer in synchronism, and a selector apparatus, operable from a central point, for regulating the speed at which. the cycle timer operates, and simultaneously selectlng'the proper circuit between the resynchronizer and the cycle timer for maintaining the latter in synchronism at the speed selected by the selector.

Referring to the drawings, l0 designates generally a circuit controller located at a central point, as for example at police headquarters. This circuit controller includes asynchronous motor comprising a rotatable disk II, and a drive coil l2. This motor is connected to a cam 33 through suitable gearing l4, l5. 'lne cam l3 periodically opens and closes a switch IS. A circuit is connected through, and controlled by, the

switch I6, which circuit is utilized to keep the synchronizers of the secondary controllers in step with each other, it for any reason any of them should get out of step.

Each secondary. controller'inchides a cycle timer designated generally as 20, a synchronizing device designated generally 2|, a selector mechanism designated generally 22, and a circuit controllerdesignated generally 23.

The cycle timer 20 includes three dials 24, 25 and 26, here shown in the formv of gears which are driven by the induction motor 21 through the pinion 28. The dials 24, 25, 26, carry adjustable fingers which make and break circuits to thesetuating mechanism of the controller 23, which in turn directly controls the display of the traffic signals at the various street intersections of the system. The detail operation of the dials 24, 25, 26, with their associated switches and the operation of the controller 23 will be described hereafter.

It is suificient to assume for the present, that the speed at which the controller 23 is operated, depends upon the speed at which the motor 21 of the timer 20 is operated. I will now describe the speed and synchronizing control apparatus for the motor 21. The motor is driven in a counter-clockwise direction (Figure 1) through the action of the driving coil 30. This coil is energized generally, by a local pick-up at the street intersection. It is to be kept in mind that the timer 2B, resynchronizer 2|, selector 22, and controller 23 comprise, in their entirety, the control apparatus located at each intersection.

The speed at which the motor 21 operates depends upon the force exerted by the bucking coil 3| which tends to operate the motor 21 in a clockwise direction. The coil 3| is energized through the wires 32, 33, 34, and, as here shown,

through the total resistance 35, wire 36, switch arm 31, brush 38, wire 39, back to the positive side of the source. It will be noted that as-the entire resistance 35 is cut into the circuit, there is relatively low voltage impressed upon the coil 3| and accordingly, produces a relative weak bucking effect to the motor 21, permitting the motor 21 to operate at a relatively high speed. Obviously, a transformer with variable taps to procure different voltages might be used in place of the resistance shown at 35.

It is to be observed that the speed at which the motor 21 will operate depends with which of the contacts the switch arm 31 of the selector 22 is in engagement.

The switch arm 31 of the selector 22 is actuated from one contact to another by any suitable mechanism. In fact, the selector itself may be of any suitable design and construction, which will effect, in the desired manner, the purpose for which it is intended. .As here shown, the switch arm 31 is carried on the shaft 40 which is rotatably mounted in suitable bearings. The shaft 40 is rotated in clockwise direction by means of the ratchet wheel 42, pawl 43, armature 44, and electromagnet 45. When the electromagnet 45 is energized, the angular armature 44 is moved clockwise (Figure 2) bringing the pawl 43 into engagement with the ratchet wheel 42. Suitable adjustable stops 46 are provided to adjust the action of the pawl 43. With this means, the shaft 40 is rotated one notch upon each time the electromagnet 45 is energized. Similar apparatus, designated generally 41, is employed to rotate the shaft 40 in a counter-clockwise direction.

45 energized by the actuation of the push button 50. These push buttons may also be located at headquarters with the controller l0. One side of the push buttons is connected to the positive side of the source through the wire 5|, the circuits The electromagnet 48 is energized. through actua- 1 tion of the push button 39, and the electromagnet I from the push buttons being: wires 52, to the cycle timer 20. It is obvious to those skilled in the traflic signaling art, that it is of utmost importance to maintain the time relation be-- tween the signals at each intersection in a pro gressive system. If this time relation varies, that is, if the signals at one intersection get out of step with the system, all of the advantages of the progressive system are lost. It is therefore necessary to provide some means to keep the control apparatus for each intersection in step with the control apparatus at-all other intersections. Heretofore, this has been accomplished by resynchronizing each secondary control once during each revolution with a master controller at' headquarters.

motor 60 of each secondary control apparatus will remain instep with the others, due to the fact that they are synchronous motors and all operated on the same frequency current. The motor operates shaft 52 through suitable gearing as 53, 34. On this shaft is mounted a plurality of cams and gears. The cams operate switches and the gears drive additional cam shafts at various speeds according to the respective gear ratio. With this arrangement each of the various switches is periodically opened and closed at various speeds. For example, assuming the shaft .62 is so geared to the motor 50 that it makes one revolution in 120 seconds, the cams 55, and 51 will likewise each make one revolution in 120 seconds. However, the switch 63 will be opened and closed once in 120 seconds, while the switch 53 will be opened and closed once every seconds, and the switch 10 opened and closed once every 40 seconds. This due to the fact that the cam 55 has one lobe, the cam 56 two lobes, and the cam 51 three lobes. The cam shafts 1|, 12, and. 13

. are each rotated through gearing of different ratios and each carry two cams, one with one lobe,

and the other with two lobes. The cam shafts 13,

15 each carry one cam. All of the switches operated by the respective cams are normally closed, and the movable contacts thereof are all connected to the common wire 15, while each of the stationary contacts are connected to respective terminals of the switch of the selector 22.

Each of these switches, operated by the cams of the synchronizer 2|, control an additional cir- .cult for the bucking coil 3| of the cycle timer 20 in the manner now described. Associated with the cycle timer 20 are normally open switches 30, Hand 82, operated by the adjustable arms 33, 83, respectively. These arms are rotatable with the dial 24, and each arm is adjustable relative to the dial. The movable contacts of these switches are all connected to the common wire 36 which in turn is connected to the wire 33 forming the positive feed for the bucking coil 3| of the motor 21. The stationary contacts of the switches 30, 8|, and 82, are connected through armatures I1, 38, of relays 89, 90, to the wire 9|, which is connected to the wire 15 which is common to all of the movable contacts of the switches as-' sociated with the synchronizer 2|. As explained above, each stationary contact of these switches is connected to a terminal of the selector 22.

I will now trace a circuit through the apparatus just previously described in the position shown in the drawings.

The brush 38 of the selector 22 is connected with the positive source of current which passes through the switch arm 31, contact 32, wire 93, normally closedswitch 10, wires 18, 3|, armatures 31, 88, tothe stationary contact of switch 80, which is normally open. As the dial 2 3 is revolved by the motor 21, thearm 83 closes the switch 80 and the circuit then continues through wires 86, 33, bucking coil 3|, wire 32, to the common side of the source. It will be remembered that bucking coil 3| previously obtained its energy through the resistance 35 and selector switch 22. In the circuit just described through the synchronizer full voltage is applied to the bucking coil 3|, and the coil now creates sufficient opposition to stop the motor 21. Each portion of the resistance 35 is such that it permits operatlon of the motor 21 through the bucking coil 3| at a speed slightly higher than that of the corresponding cam. of the resynchronizer 2| which is selected to go with that resistance. In this instance, the total resistance 35 is such that it will permit the motor 21 to operate at a speed slightly faster than that of the cam 51 which controls the switch 10 of the synchronizer. Normally, the arm 83 of thedial 24 will close the switch I!) just before the cam 61 opens the switch 13. Accordingly, the cycle timer 20 is synchronized once during every revolution of the dials by the synchronizer 2|, with the motor 50.

In the circuits just described, it will be observed that because the total resistance 35 is cut in circuit with the braking or bucking coil 3|, the motor 21 would run at comparatively high speed. Accordingly, a switch of the synchronizer is selected that is also opened and closed at a comparatively high speed. Accordingly, the cycle timer 23 may be operated at various speeds from headquarters by actuating the push buttons 49, 50, to select the speed desired and simultaneously, a corresponding resynchronizing circuit is selected whereby the cycle timer 20 may be periodically synchronized at the speed selected.

This perhaps would be better illustrated by tracing another circuit. Assume that the switch arm 31 of the selector 22 is rotated in a clockwise direction by the actuation of the push button 50 until the switch arm 31 engages the contacts Hi0, H. We will now. have only the first step of the resistance 35 cut into circuit with the braking coil 3|. In as much as nearly full voltage is impressed across the coil 3|, the braking effect will be comparatively great, and the motor 21 will run at a comparatively slow speed. Also, the resynchronizing circuit from contact will be connected through synchronizing switch 58 which is operat ed by the single lobe cam 65 which opens and closes the switch 58 at comparatively long intervals. As assumed above, if the shaft 52 revolves once every seconds, then the switch 58 will only be opened once every 120 seconds to resynchronize the cycle timer 2!! which is now operating at approximately one revolution in 118 seconds.

It will be observed that the dials 24. 25, and 26, are all geared together at a 1 to 1 ratio, and operated at the same speed by the pinion 23 of the motor 21. The arms associated with the dials 25 and 25 open and close associated switches which actuate the circuit controller 23, as hereina after explained.

Assuming the arms associated with the dials wire 9|, as shown in the drawings.

If the relay 89 is energized, the switch 8I is con-.

it will be observed that by shifting the arms 83, 84, 85, the operation of the controller 23 and the trafiic signals may be varied. To explain further: Assume switch 80 is connected in circuit with the If the arm 83 is now adjusted relative to the dial 24 in a clockwise direction, the next time the arm 83 .comes into engagement with the movable contact of switch 80, thefull voltage circuit will be completed through the braking coil 3 I, and the motor 21 will be stopped. This condition will prevail until the cam 61 of the synchronizer opens the switch 10.

In other words, the timer 20 will be stalled an amount of time equal to the distance that the arm 83 was advanced. After the cam 61 opens the switch 10, and the motor-21 starts, the timer 20 will then operate at its set speed and will be resynchronized once every revolution of the dial 25, 26, will now actuate the circuit controller 23 at a different time relative to the time that they did formerly before the variation of the arm 83.

It will now be observedthat by shifting the arm 83, the relationship between the secondary controller and its neighbors will be varied. That is, assuming the secondary controller is at intersection B and normally the green light appeared ten seconds after the appearance of the green light at A intersection, with the adjustment of the arm 83, it may be made to appear fiveseconds later, or twenty seconds later.

To those familiar with the traffic signal art,

this is known as the off-set which might be generally defined as the relative time the green light appears in each succeeding intersection in the system. I

Heretofore, as set forth in my Patent No. 1,929,- 378, the secondary controller has been provided with one ofiset arm which could only be adjusted by the operator making the adjustment at each secondary controller.

In my present invention, I provide means whereby this offset may be varied from head quarters.

As previously explained, the switch 80 is connected to the wire 9| through armatures 81 and 88 being in engagement with their lower contents, and the relays 89, 90, not being energized.

nected through armature 81, whichis then in engagement with its upper contact. When the relay 90 is energized, and its armature is in engagement with its upper contact, switch 82 is connected to the wire 9| through the'armatures 88 and 81. Means is provided at headquarters for energizing either of the armatures 89, 80. One side of relay 89 is'connected to the contact I05, and the corresponding side of the relay 90 is connected to the contact I08. The contacts I05, I06, are energized by the single pole doublethrow switch I01, the stationary contact of which is connected to the positive source of The arm 83 of the dial 24 engages the current. switch 80. switch 8|, and the contact 82.

When the secondary controller is installed at a street intersection, the arms 83, 84, and 85, are initially set to give the three most desired oifsets. Obviously, any one ofiset may be chosen from headquarters by connecting in circuit any one of the switches 80, BI, 82, by operation of the switch I01. For example, the circuit including The contact arm 84 only engages the arm 85 engages switch the switch will produce an equal flow of trafllc 24; However, the arms associated with the dials in both directions, as shownby the graph Figure 3. The selection of the circuit including the switch 8I will favor traflic moving, say to the North, as shown in Figure 4, while selection of the switch 82 and its circuits will favor traffic moving toward the South, as indicated in the graph of Figure 5.

I will'now proceed to describe the circuit con-' troller 23. This controller, as here shown, comprises a shaft IIO mounted in suitable bearings, not shown. On one end of the shaft is secured the rotor III of a motor which is driven by the coil H2. On the opposite end is an escapement mechanism which may be of any suitable design, or construction. As here shown, it comprises the escapement wheel I I3, escapement II4, which is operated in one direction by the solenoid 5, Y

upon energization of the motor coil H2 and the solenoid II5.

Obviously, any suitable step by step mechanism may be employed to rotate the shaft H0 in the desired manner. The circuit controller 23 may consist of any suitable switching mechanism operated electrically or mechanically;

The shaft II 0 isprovided with a plurality of cams. These cams operate switches which are connected in circuit with the respective traflic signals.

It is obvious that by substituting different shafts for III) with difierent cam arrangements, or substituting different cams for those shown on the shaft IIO, any desired sequence of operation may be obtained. For example, the circuit-controller 23 is now shown with the amber, or cantion, signal displayed in all four directions between signal changes, this because the amber signals of both streets are tied together by the .tooverlap, or appear simultaneously with the green at the end of the green period of duration, or overlap, or follow the red. Cam I20 operates the switch I2I, which controls the green signal indication on the main street, through the wire I22. All of the signals are connected to a common return I23. The cam I24 controls the switch I25, which operates the red signal indication on the cross street, through wire 128. The cam I21 controls the switch I28 which in turn operates the amber on the main street through wire I29. The cam I30 controls the switch "I which controls the amber on the cross street through wire I32. The cam I33 controls the switch I34, which operates the green signal on the cross street, through wire I35, and the cam I36 operates switch I31, which controls the red on the main street, through wire I38.

The shaft I I0-is shown with the cam I33 closing the switch I34 displaying the green signal to the cross street, and the cam I36 closing the I switch I 31 which displays the red signal to the signal to the cross street. The next succeeding operation will open the switches I2I; I25, and close the switch I28, again displaying the amber signal, and'the next succeeding operation again closing the switches I34, I31, displaying stop to the main street, and go to the cross street.

As stated previously, the coil II2 of the motor III, and the solenoid II5, are energized by switches associated with the dials 25, 26, of the cycle timer 20. The dial 25 is provided with adjustable arms I40, I4I', I42, and with a fixed pin I43. The pin I43 operates the switch I44, and

the arms I40, I", I42, operate the switch I45.

I will now trace the circuit through the switches I44, I45, and coil H2, and solenoid II5. Starting with the positive source (right center Figure 1) current is fed through the wires I46, 1, ar-- mature I48, wire I49, to the stationary contacts" of switches I44, I46. These switches are normally open. Assuming now,that the arm I40 engages the movable contact of switch I45, and closes the switch, the circuit now continues through wire I50, I5I, motor coil II2, wire I52, back to the common side of the source. Current is also conducted through wire I5I, solenoid II5, wire I53, to the common side of the source. As the coil I I2 and the solenoid -I I5 of the escapement mechanism are now energized, the shaft I III will be revolved one step, shifting the cams and operating the respective signal switches.

As previously stated, allof the arms I40, I, I42, operate a movable contact of the switch I45. The switch I44 is operated only by the fixed pin I43. However, the circuit from switch I44 is carried through wire I54 to the stationary contact of switch I55 associated with the circuit controller 23, which switch is operated by the cam I56. If the cam I56 is in engagement with the switch I55, and the switch accordingly closed, a positive feed is then run to the coil I I2, through the wire I56, and to the solenoid-through wire I5I, and back through wire I53, to the common side of the circuit. In other words, in order for the switch I44 to energize the coil H2 and the solenoid II5, the shaft IIO must be in such position that the cam I56 is closing the switch I55. The reason for this circuit is to keep the controller 23 in step with'the cycle tiiner 20. I

It will be observed that the cam I56 is secured to the shaft H0 in the same position as cam I30 which controls the amber signal, and when the shaft H0 is in this position, if the pin I43 operates the switch I44, the shaft IIO will be revolved one step which will close the switches I2I, I25, displaying the go signal to the main street, and red to the cross street. In other words, if the controller 23 is in step with the cycle timer 20, actuation of the switch I44 by;

the pin I43 will close the circuit to the green light on the main street. Or, in other words, the fixed pin I43 controls the commencement of the green signal duration on the main street. If however, for any reason the controller 23 has become out of step with the cycle timer 20, the coil II2 will not be energized, and the controller 23 will miss a beat, and accordingly it will miss a beat once every revolution of the dial 25 until it has again become in step.

As previously stated, the arms I40, I4I, I42, are

adjustable relative to the dial 25. If thecontroller 23 is in step with the cycle timer 20, the fixed pin I43 will control the commencement of the green signal to the main street, red to the cross street; the arm I40 will control the commencement of the duration of the amber; the arm I" apparatus for progressive traffic signaling systems, the variation of the sub-periods, or what is known to those skilled in the art, as the change of split, was accomplished by making the necessary change at each secondary controller. In my present invention, I provide means for adopting any one of a plurality of splits from headquarters. As shown in the drawings, my circuit controller is provided with means for selecting one of two different splits. This is accomplished by utilizing either dial 25, or dial 26. Obviously, any number ofadditional dials might be employed as the particular traffic situation demanded. The dial 26 is provided with arms I60, I6I, I62, which are similar to the arms I40, I4I, I42, associated with dial 25. The dial 26 is also provided with a fixed pin I63 and associated with dial 26 are two switches I64,

. I65. The arms I60, I6I, I62, operate the switch switches I44, I45, tothe switches I64, I65, a dif-' ferent split is obtained.

The means employed .for switching from one set of switches to the, other comprises a relay I66 which controls the armature I48. As shown, the relay I66 is not energized, and the armature I48 is in engagement with contact of the wire I49. The relay I66 is energized from headquarters by the switch I6'I, the movable contact of which is connected to positive side of the circuit, and when the switch I61 is closed, a circuit is made through the wire I68, to relay I66, and back through the common return 54. When the relay I66 is energized, the armature I48 is in engagementwith a contact connected to wire I63 which disconnects the switches I44,- I45, and connects the switches I64, I65 in circuit.

From the above description, it will be .obvious that with my circuit controller, as here shown, it is possible to select from headquarters, one of three oifsets, one of two splits, and one of several total periods. Generally speaking; changdecrease, the speed of operation of the progressive system in one direction. This is sometimes a material aid in handling a larger volume of trailic moving in one direction through the system. However, it is to be omerved that the duration of the signals at each intersection is not affected. However, there is a practical disadvantage which sometimes renders such a change of little value. That is, the reduction in the width of the band of traffic. This will be understood by those skilled in the art. When the speed of the system is increased, say from twenty to thirty miles per hour, the useable portion of the green, or go, signal is shortened, or in other words, the length of the trafiic platoonsmoved by the system is shortened. Where greater speed alone is desired, the adjustment of the offset is satisfactory. However, if in addition to increasing the peed of the regular flow of trafilc, there is Justment oi the ofiset does not solve the problem.

I have found that my control apparatus is very flexible and with it any traiiic problem, of which I am aware, can be readily handled from headquarters. For example, the above situation can be taken care of by what is known as the extension of the green on the main street. By thisis meant, leaving the previously allotted time to the cross street the same, and adding to the time allotted to the main street. This situation, I accomplish in the following manner: Assume that the arms I40, I4I, I42 on dial 25 are set so as to eflect a fifty-fifty split at a particular intersection, and the arms I60, ifiI, I82, are so relatively'arran'ged that the split is sixty-fifty favoring the main street. By operation or the push buttons 49, 50, at headquarters, a new total period is selected which is ten seconds longer than the period usually used with the dial'25.-

The switch I61'is then closed to switch over to this means, I have increased the green on the main street ten seconds, and have not detracted from the red, or amber,'period. It is understood that in this combination of operations, I obtain a result different from shifting from dial 25 to dial 26, or from changing the total period. The efiect of'changing the total period, or changing the splits, or changing the sets, or a combination of any of these, can be observed with the aid of graphs, Figures 3 to 9 inclusive.

Figure 6 illustrates the flow of trafllc with the green period increased at the intersections of 3rd Avenue, th Avenue, 8th Avenue and 10th Avenue, with the offset remaining the same, as shown in Q graph Figure 4.

Figure 7 is a graph showing the flow of traiilc with the green on the "main street increased at the intersections of 2nd Avenue, 4th Avenue, 6th Avenue, and 11th Avenue, with the same ofiset as 45 shown in graph Figure 5.

From the above, the'desirability of both increasing the speed of the system and broadening-the respective traihc bands is at once'apparent, and the desirability of effecting these changes from a 50 central point'is obvious. It is to be understood that the circuit controller I0 is not a necessity. Its function is to check the synchronizer 2|, or in other words, to make a double check on the secondary controllers. The shaft 62 of the synchronizer M is provided with anadditional single lobe cam I10 which operates switch I which is normally open. This switch is connected in circuit with an electromagnet I12 whichoperates an armature I13 which in turn, when operated,

60 engages a stop I14 on the motor 60. A positive source of current at headquarters is taken from the wire 5| through switch I6 which is normally closed by the cam I3, wire I15, through switch I1I, when closed, electromagnet I12, wire I16, to

65 the common return 54. I Both of the motors II and 60 are synchronous motors, and as they operate on the same frequency, they normally will remain in step with. each other. However, if for any reason the motor 60 becomes out of step with the 7 motor II, the circuit will be completed'through the electromagnet I12 by operation of the switch I1I by the cam I10. This will pull the armature I13 into engagement with the stop I14 and stop the motor 60 until the circuit is broken by the 75 movable contact of the switch I6 dropping into,

the control switch associated with dial '26. By

the 'valley of the. cam I3. This provides an additional checkon all the synchronizers. However, as all of the motors 6,0 of the synchronizers 3i are synchronous motors, there is very little likelihood of their becoming out of step, and for this reason the system will continue to operate in step if for any reason the circuits running from any of the secondary controllers become open, or who! order. In such instance, the secondary controller will operate on the split determined at the time such circuits become open.- The offset would be that determined by the arm 83. In other words, the same as ifswitch I01 was inthe position shown (open), relays 89, 90 being deenergized.

For convenience, an indicating device may be also added at headquarters to indicate, at any instance, the position of theselector 22 and therefore indicate the total period at which the system is at that instance operating. Such a device is indicated at 2M, and may be of any suitable design or construction. For example, it could be of the same construction as theselector 22, except the switch arm 31 would be replaced with the pointer 202. This indicating device '2III is connected in circuit with the wires 52, and

upon operation of the push buttons 49, 50, the pointer 282. will indicate the position assumed by the switch 31 of the selector 22.

, What Iclaim is:

1'. In a synchronizing system, a first constant,

speed motor, a second motor, a circuit for energizing said second motor including an impedance for controlling the speed of said second motor, means to vary said impedance to select the speed of operation of said second motor, circuit means to synchronize the two said motors to rotate at each of a plurality of predetermined 1 speed ratios at a particular phase relation, said last means including switches capable of selective connection in said circuit means and means operated by said first motor for cyclically operating said switches, each at predetermined periods, means operated by, said impedance varying means to connect in-said circuit means the one of said switches that maintains said motors in synchronism at the speed ratio corresponding to the amount of impedance simulta- "neously connected in said circuit by the impedance varying means.

2. In a traiiic control system station for flexibly controlling progressive trafllc having acentral through a plurality of intersections and also I having at each intersection: stop and go traffic signals, a first constant speed motor, a second motor, a circuit for energizing said second motor including an impedance for controlling the speed of said second motor, means to vary said impedance to select the speed of operation of said second motor, circuit means to synchronize the two said motors to rotate at each of a plurality of predetermined speed ratios at a particularphase relation, said last means including switchesrcapable of selective connectionin said circuit means and means operated by said first motor for cyclically operating said switches, each speed ratio corresponding to the amount of impedance simultaneously connected in said circuit by the impedance varying means, and means operated by a predetermined number of revolutions of saidsecond motor regardless of its speed for alternately displaying in a predetermined ratio said stop and go signals in a single cycle whereby variations of speed of said second motor vary the total period of said cycle.

3. In a traffic control system having a central station for flexibly controlling progressive traflic through a plurality of intersections and also having at each intersection: stop and go trafli'c signals, a first constant speed motor, a second motor, a circuit for energizing said second motor including an' impedance for controlling the speed of said second motor, means to vary said impedance toselect the speed of operation of said second motor, circuit means to synchronize the two said motors to rotate at each of a plurality of predetermined speed ratios at a particular phase relation, said last means including switches capable of selective connection in said circuit means and means operated by said first motor for cyclically operating said switches, each at predetermined periods, means operated by said impedance varying means to connect in said circuit means the'one of said switches that maintains said motors in synchronism at the speed ratio corresponding to the amount of impedance simultaneously connected in said circuit by the impedance varying means, and means operated by a predetermined number ofrevolutions of said second mote regardless of its speed for alternately displaying in a predetermined ratio said stop and go signals in a single cycle whereby variations of speed of said second motor vary the total period of said cycle, said circuit means also includes switches periodically operated by said second motor and selectively connected in said circuit means to determine the pa ticular. phase at which the said motors will be synchronized, means to connect selectively the last said switches in said circuit closers whereby the'signal offset at a plurality of intersections can be controlled.

4. In a traffic control system having a. central station for flexibly controlling progressive traffic through a plurality of intersections and also having at 'each intersection: stop and go traffic signals, a first constant speed motor, a second motor, a circuit for energizing said second motor including an impedance for controlling the speed of said second motor, means to vary said impedance to select the speed of operation of said second motor, circuit means to synchronize the two said motors to rotate at each of a plurality of predetermined speed ratios at a particular phase relation, said last means including switches capable of selective connection in said circuit means and means operated by said first motor for cyclically operating said switches, each at predetermined periods, means operated by- .for alternately'displaying in a predetermined ratio said stop and go signals in a single cycle whereby variations of speed of said second motor vary the total period of said cycle, said circuit means also includes switches periodically operated by said second motor and selectively connected in said circuit means to determine the particular phase at which the said motors will be synchronized, means to connect selectively the last said switches in said circuit closers whereby the signal offset at a' plurality of intersections can be controlled, means for selecting the said ratio ofstop and go signals in said cycle whereby the signal split is controlled, and means at said central station for operating said impedance varying means, oifset varying means and split varying means for the various intersections.

5. A traflic control system for flexibly controlling progressive traihc through a plurality of intersections and having at each intersection: stop and go signals, a variable speed motor, a power circuit for controlling said motor including a plurality of means, each of which is effective to operate said motor at a different rate of speed, a constant speed motor, a plurality of switches operated by said constant speed motor, each of said switches being operated at a different rate of speed, a control circuit, means operable to render any predetermined one of said means in the power circuit of the variable speed motor operable and to simultaneously connect any predetermined one of said switches in said control circuit, said control circuit also including means operable to periodically synchronize said variable speed motor with said switch connected in said circuit, and a timer operated by said variable speed motor for cyclically displaying said stop and go trafiic signals.

6. A traflic control system having a central station forflexibly controlling progressive traffic through a plurality of intersections and also having at each intersection: stop and go traffic signals, a variable speed motor, a power circuit for controlling said motor including a plurality of means, each of which is efiective to operate said motor at a different rate of speed, and said means being capable of selective connection in said circuit, a constant speed motor, a plurality of switches operated by said constant speed motor, each at a different rate of speed, a control circuit, means operable to connect any predetermined one of said means in the power circuit of the variable speed motor and to simultaneously connect any predetermined one of said switches in said control circuit, said control circuit also including a. plurality of switches periodically operated by said variable speed motor and each being selectively connected in said control circuit and operable to periodically synchronize said variable speed motor with said switch operated by the constant speed motor and connected in the control circuit at a predetermined phase relation therewith, means operable at the central station for connecting any one of said switches operatedby the variable speed motor in said control circuit, and a timer operated by said variable speed motor for cyclically displaying.

said stop and go traffic signals.

CARL H. BISSELL. 

